You also note that:
• The discharge air temperature is what you would expect it to be for this gas-fired heating system.
• Turning the thermostat to a lower set point and waiting a reasonable time proves that the indoor blower motor doesn’t shut down.
When you access the unit’s electrical system, you note that the burners are operating normally since the thermostat is again calling for heat, and you begin your troubleshooting procedure by placing a voltmeter at H1 and H2 on the IBDR coil and confirm 24 vac. When you instruct the customer to turn the thermostat down to a lower set point, you note that the burners shut down, and after a delay, your voltage reading at IBDR is 0 vac, while the indoor blower motor continues to operate. Your next voltage test is at #2 and #4, M1 and M2, and your reading is 0 vac.
Your troubleshooting question: What is your next step in solving this problem?
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